Twin blade injector unit

ABSTRACT

A blade unit adapted to be inserted in a standard single cutting edge injector type safety razor, the unit comprising a pair of superposed blades with an intervening spacer all permanently secured together, the spacer terminating short of the advance end of the unit and the blades at that end being capable of flexing toward each other.

O United States Patent 1 1 1111 3,872,592

Iten Mar. 25, 1975 [54] TWIN BLADE INJECTOR UNIT FOREIGN PATENTS OR APPLICATIONS Inventor: Clemens A. Iten, Staunton, Va. 772,532 4/1957 United Kingdom 30/50 [73] Assignee: Philip Morris Incorporated, New

York, NY. Primary Examiner-Al Lawrence Smith Assistant Examiner-Gary L. Smith [22] Flled' 1974 Attorney, Agent, or FirmWatson Leavenworth [21] Appl. N0.: 437,859 Kelton & Taggart [52] US. Cl. 30/346.58, 30/50 [57] ABSTRACT [51] B26) 21/54 B26b 21/22 A blade unit adapted to be inserted in a standard sin- [58] ml 0 earc 30/50, 346.57,,34658, gle Cutting edge injector type Safety razor the unit 3084659 305 comprising a pair of superposed blades with an intervening spacer all permanently secured together, the [56] References cued spacer terminating short of the advance end of the UNITED STATES PATENTSv unit and the blades at that end being capable of flex- 2,654,149 10/1953 Bowen 30/65 X ing owar each other. 3,262,206 7/1966 Tomer 1 1 30/50 X 3724070 4/1973 Dorian 30/50 X 8 Claims, 5 Drawmg Flgures TWIN BLADE INJECTOR UNIT BACKGROUND OF THE INVENTION The invention is in the art of injector type safety razors having replaceable blades adapted to be inserted from a blade holder dispenser. Details of the razors and dispensers common in the art vary considerably but in general the razors are characterized by having the blade clamped between a bridge or platform and an overhanging cap, the dispenser having a tang insertable in the razor head to open up a space sufficient to free the blade and thereupon a slide on the dispenser is manipulated to push forward the blade into the razor head, the advancing end engaging the used blade and pushing it out of the razor head. The dispenser tang is then withdrawn leaving the new blade in clamped position in the razor head. Reliable blade changing operation depends upon the forward end of the incoming blade engaging the outer end of .the blade in the head and pushing it from the razor and not by-passing the end of the used blade. Many patents have issued covering variations in this type of injector razor, the patents to Butlin No. 2,701,910 and Kuhn] No. 2,911,713 being representative. Commonly the bridge or platform has an opening or series of openings just rearwardly-of the guard or soap bar whereby soap and debris in general may escape therethrough from under the forward cutting edgeof the blade.

GENERAL DESCRIPTION OF THE INVENTION The present invention concerns a twin or double in jector blade unit comprising two superposed blades permanently secured together with an intervening spacer, the cutting edge of the top blade being spaced rearwardly a small distance from the cutting edge of the lower blade. The U.S. Pats. to Gray No. 1,975,757 and Tomek No. 3,262,206 disclose various forms of such a blade arrangement in general. Also the British Pat. No. 772,532 of 1957 shows a blade unit of the type having a pair'of superposed double edge blades secured together with an intervening spacer.

The normal injector type razor is designed to receive the standard single edge blade having a thickness commonly in the range of 0.01 'to 0.012 inch. Excessive opening of the razor by the dispenser tang must be avoided otherwise the ingoing blade end may slip past the end of the used blade in the razor resulting in jamming. Under the circumstances the replacement blade unit of the type concerned must be limited in thickness. One double injector blade unit presently on the market comprises merely two blades secured directly together having overall thickness of about 0.020 of an inch.

The double blade unit of the present invention embodies a spacer but the individual blades are made thiner, each having a thickness of about 0.006 of an inch and the spacer a thickness of about 0.008. The overall thickness thereby being about 0.020 of an inch. However, to ensure ready entrance of the blade into the razor head the spacer is shaped to terminate a short distance from the normally razor entering end of the unit. Injector razors of this type commonly in use have a rounded or coined bevel at the right end of the bridge at the blade entering end and in most cases also the corresponding end of the cap also has at least a slight radlus, enabling the ready entrance of the present type blade unit. This results particularly from the fact that the spacer being terminated short of the end of the blade unit at the razor entering end, as the pair of individual blade ends enter the razor head they are deflected toward each other ensuring that the end of the blade unit engages the used blade in the razor pushing it out and avoiding any by-passing or jamming of the blades.

Other details and features will become apparent from a consideration of a representative blade unit as described hereinafter and shown in the drawing in which:

FIG. 1 is an exploded view of the three elements comprising the blade unit.

FIG. 2 is a top plan view of the assembled parts.

FIG. 3 is a bottom plan view of the assembled parts.

FIG. 4 is a cross-sectional view taken on the plane 44 of FIG. 2.

FIG. 5 is a view in perspective indicating the procedure and effect of the injection of the unit in a representative type injector razor.

The blade unit comprises three elements, a top blade 10, a spacer-11 and a bottom blade 12. The blades 10 and 12 which are of the usual steel material may be identical as a matter of convenience and economy in manufacture. The top blade has its cutting edge 14 set back from the cutting edge 15 by a small distance such as about l/32 of an inch. Each blade has a width of about 0.315 of an inch and the overall width of the assembled unit is slightly larger with a maximum of about 0.350 of an inch. The blades each have rectangular openings 16 which are utilized in the manufacture of the blade strip and they have no function in the final unit as employed in a razor. The spacer element 11 may be made of any one of various materials such as metal or plastic but preferably is composed of stainless steel corresponding to the material in the blades which preferably is stainless steel. The back edge 17 of the spacer may coincide with the back edge 18 of the lower blade 12 as indicated in the cross-sectional view of FIG. 4, although it is not a necessary condition.

The method of joining the three elements may be varied as by mechanical means, such as staking or bent tabs or it may be by adhesive bonding including application of heat or by pressing or soldering or welding. In the specific form disclosed the preferred method of joining is by spot welding. In the case of a plastic spacer examples of assembly methods are hot staking or ultrasonic staking. Also if desired each of the blades near its front cutting edge is provided with a row of openings such as the slots 20 which are adapted to serve a function to be later described. As is indicated in FIG. 4 the front edge 21 of the spacer is positioned rearwardly of the slots 20 in the bottom blade for a purpose which will be described shortly. Of importance is the fact that the forward end 25 of the spacer terminates short of the end 26 of the two blades and the unit as a whole. Within limits the space between the end 25 of the spacer and the end 26 of the unit may vary, depending somewhat on the thickness of the spacer and of the respective blades among other factors but desirably is in the range below about /8 of an inch and preferably about 1/16 of an inch as in the embodiment shown. The three elements are in the present embodiment spot welded together at a series of spaced points which in the present case comprises three points, 28, 29 and 30. The position of the spot weld 28 is of some importance and should be relatively close to the end 25 of the spacer to reduce or avoid any tendency of the ends of the blades to be deflected away from each other at that 3 end of the unit and preferably the ends of the blades may incline toward each other for the reason to be discussed shortly.

The thickness of each of the three elements may vary somewhat within practical ranges providing the overall thickness is not too great which in most cases is preferably in the range below about 0.025 of an inch. The blades should be in the range of 0.004 to 0.008 of an inch and the spacer in the range preferably of 0.006 to 0.010 of an inch. As a specific preferred combination the blades are each 0.006 of an inch in thickness and the spacer is 0.008 of an -inch in thickness, the unit thereby having an overall thickness of 0.020 of an inch.

The importance of the spacer terminating short of the end 26 of the unit will be apparent from the manner of insertion of the blade unit in a typical injector razor. This is pictured in FIG. 5. As previously described the edge 31 of the bridge 33 and usually also the edge 32 of the cap member 35 are each somewhat rounded. The illustration in FIG. assumes that by insertion of the normal dispenser tang the bridge member 33 is sprung away from the cap member 35 aslight amount whereby the used blade in the razor is released from the stop elements 34 on the bridge and the clamping action on the blade between the cap and bridge members is slightly relieved whereby the blade in the razor is free to be moved outwardly to the left.

As the blade unit 36 is advanced into the mouth of the razor head the radii 31 and 32 facili'tate the initial entrance of the blade unit and immediately after the initial entrance the ends of the two blades are deflected toward each other as indicated at 38 which assures that the forward end of the unit willengage the rear end of the blade in the razor and will slide the used blade outwardly to the left, whether it is a standard blade having a thickness of no more than about 0.012 of an inch or is a unit similar to that being inserted.

It may be noted that injector razors of the type involved usually have a slot extending down through the bridge or a series of slots. FIG. 5 shows a single slot 40, and as previously mentioned the blades have a row of holes 20 near their cutting edge. By reference to FIG. 4 it will be apparent that the soap and other debris in shaving collecting below the bottom blade 12 will have a flow path down through the opening 40 and furthermore debris collecting under the forward edge of the top blade between it and the bottom blade 12 will have a somewhat free escape through the openings in the bottom blade and may continue on down through the bridge opening 40.

A representative embodiment of the invention has been disclosed and described but it will be apparent that various changes may be made in the details of the blade unit some of which have been indicated and different embodiments of the invention made without departing from the principles thereof and it is intended that all matter contained herein shall be interpreted as illustrative and not necessarily in a limiting sense.

What is claimed is:

1. A safety razor injector blade unit adapted to be inserted in and fit a single edge injector razor, said unit comprising two thin blades each with a forward cutting edge and an intervening thin spacer, said blades and spacer being permanently secured together, the cutting edge of each blade extending for substantially the entire overall length of the respective blade, said unit having a first end adapted to be the advance end of the unit in insertion in the razor, the spacer occupying the major portion of the length of the unit but terminated short of said first end and the blade cutting edges, whereby upon insertion of the unit in a razor the corresponding ends of the blades may flex toward each other.

2. A safety razor injector blade unit in accordance with claim 1 in which the blades each have a thickness of not more than 0.008 of an inch, and the spacer has a thickness of not more than 0.010 of an inch.

3. A safety razor injector blade unit in accordance with claim 1 in which the overall thickness of the unit is within the range below 0.025 of an inch.

4. A safety razor injector blade unit in accordance with claim 1 in which the blades each has a thickness of about 0.006 of an inch and the spacer has a thickness of about 0.008 of an inch.

5. A safety razor injector blade unit in accordance with claim 1 in which the spacer is terminated short of the advance end of the unit by a distance in the range of below about of an inch.

6. A safety razor injector blade unit in accordance with claim 1 in which the forward cutting edge of the top one of the blades is set back of the forward cutting edge of the other blade.

7. A safety razor injector blade unit in accordance with claim 1 in which the lower blade has exposed openings therein between its cutting edge and the edge of the spacer.

8. A safety razor injector blade unit adapted to be inserted in and fit a single edge injector razor, said unit comprising two thin blades each having a thickness in the range of0.004 to 0.008 of an inch and each having a forward cutting edge extending for substantially the entire overall length of the respective blade, and an intervening thin spacer having a thickness in the range of 0.006 to 0.010 of an inch, said blades and spacer being permanently secured together to form a unit having an overall thickness below 0.025 of an inch, said unit having a first end adapted to be the advance end of the unit in insertion in the razor, the spacer occupying the major portion of the length of the unit but terminated short of said first end and the blade cutting edges by a distance of about 1/16 of an inch, whereby upon insertion of the unit in an injector razor the corresponding ends of the blades may flex toward each other.

iii; 53E PATENT OFFlCE CERTiFECATE OF CORRECT-ION PATEM no. 3,872,592

DATEU :March 25, 1975 iwVENTORi'S') Clemens A. Item it is, armed thai. EHOI PPM-TS m the above--identified patent and that said Letters Patent hem-b corrected as shown bmow:

Col. 4, claim 5, line 31 "150" should read -l/8-- Signed and Sealed this i twenty-second Day Of July 1975 [SEAL] A rresr:

RUTH c. MASON Arresting Officer C. MARSHALL DANN Commissioner of Patents and Trademarks 

1. A safety razor injector blade unit adapted to be inserted in and fit a single edge injector razor, said unit comprising two thin blades each with a forward cutting edge and an intervening thin spacer, said blades and spacer being permanently secured together, the cutting edge of each blade extending for substantially the entire overall length of the respective blade, said unit having a first end adapted to be the advance end of the unit in insertion in the razor, the spacer occupying the major portion of the length of the unit but terminated short of said first end and the blade cutting edges, whereby upon insertion of the unit in a razor the corresponding ends of the blades may flex toward each other.
 2. A safety razor injector blade unit in accordance with claim 1 in which the blades each have a thickness of not more than 0.008 of an inch, and the spacer has a thickness of not more than 0.010 of an inch.
 3. A safety razor injector blade unit in accordance with claim 1 in whiCh the overall thickness of the unit is within the range below 0.025 of an inch.
 4. A safety razor injector blade unit in accordance with claim 1 in which the blades each has a thickness of about 0.006 of an inch and the spacer has a thickness of about 0.008 of an inch.
 5. A safety razor injector blade unit in accordance with claim 1 in which the spacer is terminated short of the advance end of the unit by a distance in the range of below about 150 of an inch.
 6. A safety razor injector blade unit in accordance with claim 1 in which the forward cutting edge of the top one of the blades is set back of the forward cutting edge of the other blade.
 7. A safety razor injector blade unit in accordance with claim 1 in which the lower blade has exposed openings therein between its cutting edge and the edge of the spacer.
 8. A safety razor injector blade unit adapted to be inserted in and fit a single edge injector razor, said unit comprising two thin blades each having a thickness in the range of 0.004 to 0.008 of an inch and each having a forward cutting edge extending for substantially the entire overall length of the respective blade, and an intervening thin spacer having a thickness in the range of 0.006 to 0.010 of an inch, said blades and spacer being permanently secured together to form a unit having an overall thickness below 0.025 of an inch, said unit having a first end adapted to be the advance end of the unit in insertion in the razor, the spacer occupying the major portion of the length of the unit but terminated short of said first end and the blade cutting edges by a distance of about 1/16 of an inch, whereby upon insertion of the unit in an injector razor the corresponding ends of the blades may flex toward each other. 